Generalization of coupled wave equations by considering off-Bragg diffraction in photorefractive BTO crystal

This theoretical study is about generation of two higher order diffraction beams by considering off-Bragg diffraction in an optically active, absorptive photorefractive crystal of 23 symmetry in diffusion regime. This study has been done via two-wave mixing in transmission geometry in Bismuth Titanium Oxide (BTO) crystal. Effect of input beam polarization state and off-Bragg parameter has been studied on the output beam intensities. It has been observed that the off-Bragg parameter should be optimized to a low value for coupling significant energy to the higher order beams. It has also been observed that by varying input polarization angle of pump beam, the properties of output higher order beams such as amplitude, polarization can be modified. This feature can be utilized in optical beam splitter and optical interconnects etc. © Optical Society of India 2012.